SARAH FERGUSON, PRESENTER: You might think that the craze in body art couldn't get any bigger than it already is, but tattoos have become so common that enthusiasts are searching for ever more outrageous body modifications, as they're known. For example, eyeball tattoos and tongue splits. If you haven't seen one it's worth staying with us, although it's not for the squeamish as our reporter Monique Schafter found.

MONIQUE SCHAFTER, REPORTER: From brightly coloured sleeves to elaborate neck tattoos, it can be hard to find ink free skin these days.

TATTOO ARTIST: I've been tattooing for over 20 years. To the average person that wouldn't have got one 10 years ago is now getting them and they're getting them big.

TONY, TATTOO ARTIST: When you look around here tattooing now the faces, the neck, it's overboard, you know what I mean? Like how these people are going to feel in 30 years' time? It's gone to the limit.

MONIQUE SCHAFTER: On the weekend a massive 20,000 punters attended the Australian tattoo and body art expo in Sydney - up from 16,000 last year. The event attracts a mixture of local and international body artists, art lovers and human canvass looking to push the boundaries of self expression.

KIAN, TATTOO ARTIST: It's that one upmanship, you know. So to stand out at 20 years old they're getting tattooed down to here and they're getting all this stuff.

MONIQUE SCHAFTER: Now that tattoos have crept into the mainstream, individuals are finding new ways to stand out from the pack.

Amongst the new wave of body modifications are eyeball tattoos.

BRENDAN, BODY MODIFICATION ARTIST: It's like a white sort of tattoo ink that we put in there. So if you look really close into the eye it's like one normal eye and one white eye and then yeah, the magic just rolled from there. I wanted something a little more subtle so it looked like basically you're staring at me and it's like I've got one glass eye and one normal eye.

MONIQUE SCHAFTER: Howard, also known as LunaCobra, is an internationally renowned body modification artist whose work extends far beyond conventional tattoos and piercings.

LUNACOBRA, BODY MODIFICATION ARTIST: My brother's a plastic surgeon, my father's a doctor, my mum is a medical illustrator and a surgical technician. So I think all these elements came to help me do what I do today.

MONIQUE SCHAFTER: Based in Sydney, Howard was the first person to tattoo an eyeball for artistic purposes.

LUNACOBRA: My thing is I don't touch an iris or go anywhere near it. All I do is touch the sclera and I'm just, so just the white part of the eye and I make it a colour and that's it. Eyeball tattooing is done for a very long time, I think since the 1800s or before, but on non-sighted eyes and normally to correct, you know, an abnormality like damage or something, just making that look normal again.

KYLIE, BODY PIERCER: I just really like the look of it. I think it looks cartoony which is cool, makes you look not human so much. Yeah, I just really like it.

MONIQUE SCHAFTER: Kylie, a body piercer who works with Howard, braved the procedure.

LUNACOBRA: The lids are held open gently, of course, otherwise you bruise it. And then it's just kind of hand done. So it's like a hand poking procedure of where you just go in that certain layer. You don't have actual nerve endings in your eyeball itself, so if you notice you put in contacts or something it just feels weird, you don't feel pain in your eye.

MONIQUE SCHAFTER: How many eyeball tattoos have you done over the years now?

LUNACOBRA: I've done hundreds of eyeball tattoos now. It's the most permanent tattoo you can get because you can't laser it off.

MONIQUE SCHAFTER: What did it feel like when you had it done?

KYLIE: It wasn't painful, it was just really, really scary. I think afterwards I sort of I cried because I was so glad it was over and I was really happy but it's just very intense, probably the most intense thing I've ever had done, but yeah.

It Sort of feels like you've got a bit of sand in your eye, you feel like pressure and that's about it.

MONIQUE SCHAFTER: Howard performs a range of other extreme body modifications on people who want to look different.

MONIQUE SCHAFTER: Not content with just a tongue piercing, Heath took it one step further.

HEATH: I had a tongue split. It wasn't a pleasant experience but at the end it's awesome, I love it.

MONIQUE SCHAFTER: Does it make eating any different?

HEATH: Eating is amazing but I think more taste buds developed on the surface area that was exposed, so everything takes awesome now.

MONIQUE SCHAFTER: Any risks with particular kinds of body art?

LUNACOBRA: I think there's tonnes of risks with all types of body art. There's a lot of stuff that could go wrong and that's why if you don't have a basic understanding of anatomy, and I mean having, taken a class in anatomy at university, if you haven't at least done that then I don't think you really care about the art or your subject.

BRENDAN: I don't want people to go whoa, my God straight away. I want them to sort of go "What's going on there?" - be mysterious.

MONIQUE SCHAFTER: What kind of modifications do you have?

LUNACOBRA: I don't have a whole lot. I'm kind of a normal one always in the group.

SARAH FERGUSON: You think you're shocked, you should see the look on the floor manager's face in the studio tonight.